Tool for sealing a pressure-operated dispensing container

ABSTRACT

The invention contemplates a pressurized container, as for the containment of viscous product to be selectively dispensed, and relying on an internal piston as the means of constantly loading the product for displacement in the direction of dispensing nozzle. The base of the container is closed by a resilient plug, jammed into a converging concave formation that is so configurated, in relation to a pressure-charging and pluginserting tool, as to assure unerring closure without charge leakage, and at the same time to have the tool universally effective in performing its function for a wide range of container sizes.

United States Patent [191 Schultz [111 3,827,212 [451 Aug. 6, 1974 [75] Inventor: Robert S. Schultz, Old Greenwich,

Conn.

[73] Assignee: Eyelet Specialty Company,

Wallingford, Conn.

[22] Filed: Nov. 10, 1972 [21] Appl. No.: 305,304

52 Us. Cl. 53/88, 53/43 [51] Int. Cl B65b 31/04 [58] Field of Search 53/43, 88, 319

[56] References Cited UNITED STATES PATENTS 3,124,917 3/l964 Dobbins 53/88 3,204,387 9/1965 Scheindel 53/43 X TOOL FOR SEALING A PRESSURE-OPERATED DISPENSING CONTAINER 3,654,743 4/1972 McGeary 53/88 Primary Examiner-Travis S. McGhee Attorney, Agent, or Firm-Sandoe, Hopgood and Calimafde [5 7 ABSTRACT The invention contemplates a pressurized container, as for the containment of viscous product to be selectively dispensed, and relying on an internal piston as the means of constantly loading the product for displacement in the direction of dispensing nozzle. The base of the container is closed by a resilient plug, jammed into a converging concave formation that is so configurated, in relation to a pressure-charging and plug-inserting tool, as to assure unerring closure without charge leakage, and at the same time to have the tool universally effective in performing its function for a wide range of container sizes.

4 Claims, 4 Drawing Figures TOOL FOR SEALING A PRESSURE-OPERATED DISPENSING CONTAINER This invention relates to a particular feature of pressurized-container construction at the region of pressure-charging, and to coacting tool structure and procedure having to do with pressure-charging and sealing the container.

It is an object of the invention to provide an improved construction and method of the character indicated.

A specific object is to meet the above object with tool structure which is inherently self-centering at the pressure-charging port of the container and which is universally applicable to a range of container sizes.

A general object is to achieve the above objects at reduced cost and greater efficiency than heretofore.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specifi cation, in conjunction with the accompanying drawings. In said drawings:

FIG. 1 is a longitudinal sectional view through a pressurized container, which has been pressurized by the means and method of the invention;

FIG. 2 is a fragmentary longitudinal sectional view through cooperating container and charging-tool parts, in accordance with the invention;

FIG. 3 is a view similar to FIG. 2, to illustrate cooperating parts in a subsequent relationship; and

FIG. 4 is a view similar to FIG. 2, to illustrate a modification.

In FIG. 1, the invention is shown in application to a cylindrical pressurized container or can 10, with an integral conical top-end wall 11, and provided with a valve 12, for the dispensing of viscous product from the region 13 within the container. The valve 12 is of the variety in which a valve stem 14, is resiliently supported by an elastomeric bushing 15 and is pressed laterally in a well-known manner in order to open the valve seal and permit viscous product, which is at superatmospheric pressure, to be expelled to the atmosphere.

The open lower end of the container body is permanently closed by an upwardly domed end wall 16, at a peripherally continuous chimed connection 17, and a resilient elastomeric plug 18 at a central opening '19 seals off the pressurized contents. Within the container, a movable piston 20 having an integral peripheral flexible seal flange 21 establishes an interior division between the viscous-product region 13 and a pressurizedgas chamber 22 beneath piston 20. As shown, a clearance A between flange 21 and the primary skirt or body 23 enables piston 20 to maintain a smooth upwardlyriding sealed division between the interior regions 13-22, as dictated by the extent to which product has been dispensed, and in spite of surface irregularities, such as dents, in the inner wall surface 10a of the container body.

FIG. 2 illustrates the relationship between the container opening 19 and a pressure-charging and sealing tool 25. In accordance with a feature of the invention, the opening 19 is at the inner end of an inwardly taper ing concavity or mouth 26, the same being shown as frusto-conical at a taper angle a to the container axis 27 and in the range of 45 to 75, i.e., making an included angle in the range 90 to 150, preferably about A short axial flange portion 28 provides assurance of a smoothly defined throat for opening 19, avoiding burrs or a sharp edge at the region of greatest compression of plug 18. The tool 25 is generally cylindrical, with a nozzle end having a convex tapered surface 29 which matches and therefore accurately centrally aligns with the concave taper of mouth formation 26, as shown. The interior of tool 25 includes a guide bore 30 sized to accommodate a plug element 18 in relatively unstressed condition, positioned by piston means 31, in readiness for upward displacement into plugging relation with opening 19; the tool bore tapers inwardly to a minimum extent at a discharge-exit or throat end 32, of diameter corresponding substantially to that of the throat region 28 of opening 19. It will be appreciated that, with the tool 25 fitted to mouth 26, as suggested by arrows F indicative of applied compressive abutment of the nozzle with respect to mouth 26, a substantially smooth and continuous passage is presented to the radially compressed plug 18, in the course of plug insertion; the plug-insertion force is sug gested by arrow F,,, and a flexible platform 33 forming part of piston means 31 yields radially to permit plug 18 to be axially driven to the desired extent (FIG. 3). Prior to plug insertion, a passage 34 communicates gas under pressure to the container via the nozzle passage 32, the supply and control means therefor being schematically suggested by a heavy broken arrow 35; gastight connection from nozzle to container is provided by an elastomeric annulus or O-ring 36, surrounding the fit of the tapering surfaces 26-29 and sufficiently thick to be circumferentially continuously compressed between adjacent surfaces 29-16 under the force F,,.

The procedure for gas-charging the container 10 is seen to involve selection of matched concave and convex contours at 26-29, supplying a requisite quantity of pressurized gas via means 35-34 in the pressence of the force F and applying force F to drive plug 18 into home position (FIG. 3). Once the FIG. 3 position of plug 18 is reached, piston means 31 and tool 25 may be retracted, and it will be understood that the selfexpanded head end 37 of plug 18 will sufficiently axially retain plug 18, to permit smooth and clean withdrawal. After tool withdrawal, self-expansion of the tail end 38 of plug 18 will expand the region of resiliently loaded circumferentially continuous seal action, from throat 28 to a substantial adjacent surface area of the mouth 26, as will be understood.

In the arrangement of FIG. 4, the parts are similar, except for the use of fitted inwardly tapering concave and convex surfaces 26'-29' which are frustospherical, rather than frusto-conical as in FIG. 2. The discharge-exit of the nozzle at diameter 32' again substantially conforms to that at the throat 28' of mouth formation 26. Preferably, the arcuate extent of the convex truncation 29' slightly exceeds that of the concave truncation 26', thus permitting a small extent 8 of angular self-aligning adaptation upon application of the force F,. Other parts of FIG. 4 are as in FIG. 2 and are fully described by use of the same reference numerals, with primed notation.

The described structural relation and method will be seen to have met all stated objects, assuring an accurately centered fit of the charging tool to each successive container, and without permitting any plug-fouling or plug-marring discontinuity at the throat region 32-28. There is no need for any referencing reliance on the chime 17, as in the past, and thus the invention is applicable to a wide variety of container shapes and sizes, as suggested for example by phantom outlines for a bottom wall 40 and container body 41 of substantially greater diameter than container 10. The only point in common with all such different sizes, contours and shapes, is that the mouth formation 26 (26) shall be the same, to permit service by the same charging tool 25 (25').

In a typical successful employment of the invention, the mouth 26 has an included taper angle (2a) of substantially 120, to a throat (28) diameter of 0.140 inch and length of substantially 0.031 inch, for accommodation of a synthetic rubber plug (18) of 5/ 16-inch length, cut from 0.200 to 0.250 diameter stock, the latter being selected for its toughness, resilience, and cutresistance.

While the invention has been described in detail for the preferred forms shown, it will be understood that modifications may be made without departing from the claimed invention.

What is claimed is:

1. A pressure-charging tool for use with a pressurechargeable container, said container having an upwardly domed bottom closure wall with a generally central charging opening, said opening being defined at the small end of an inwardly tapering concave mouth formation having circumferential symmetry about a filling axis, said tool including a generally cylindrical nozzle of external diameter exceeding that of said mouth, said nozzle having a convex surface of taper substantially matching that of said mouth and further having an exit-bore diameter substantially matching the minimum diameter of said mouth, and the bore of said nozzle tapering inwardly to a throat at said exit-bore diameter; whereby upon application of axially compressive force between said nozzle'and mouth, and with said concave and convex surfaces in fitted relation, (a) the exit bore relatively smoothly and concentrically registers with the charging opening, (b) a resilient cylindrical plug of diameter exceeding exit-bore diameter may be continuously radially compressed in an axial insertion to plug the opening, and (c) the part of the plug which is externally exposed upon tool removal can expand into smooth and continuous resilient sealing engagement with the charging opening and with an adjacent circumferentially continuous portion of the wall of said mouth formation.

2. The tool of claim 1, in which said tapering convex and concave surfaces are conical.

3. The tool of claim 1, in which said tapering convex and concave surfaces are frusto-spherical.

4. The tool of claim 3, in which the included effective angular extent of said convex surface exceeds that of said concave surface. 

1. A pressure-charging tool for use with a pressure-chargeable container, said container having an upwardly domed bottom closure wall with a generally central charging opening, said opening being defined at the small end of an inwardly tapering concave mouth formation having circumferential symmetry about a filling axis, said tool including a generally cylindrical nozzle of external diameter exceeding that of said mouth, said nozzle having a convex surface of taper substantially matching that of said mouth and further having an exit-bore diameter substantially matching the minimum diameter of said mouth, and the bore of said nozzle tapering inwardly to a throat at said exit-bore diameter; whereby upon application of axially compressive force between said nozzle and mouth, and with said concave and convex surfaces in fitted relation, (a) the exit bore relatively smoothly and concentrically registers with the charging opening, (b) a resilient cylindrical plug of diameter exceeding exit-bore diameter may be continuously radially compressed in an axial insertion to plug the opening, and (c) the part of the plug which is externally exposed upon tool removal can expand into smooth and continuous resilient sealing engagement with the charging opening and with an adjacent circumferentially continuous portion of the wall of said mouth formation.
 2. The tool of claim 1, in which said tapering convex and concave surfaces are conical.
 3. The tool of claim 1, in which said tapering convex and concave surfaces are frusto-spherical.
 4. The tool of claim 3, in which the included effective angular extent of said convex surface exceeds that of said concave surface. 